1. Field of the Invention
This invention relates to radio direction finding equipment.
2. Description of the Prior Art
Radio direction finder systems exist in the prior art in a number of forms. The type of direction finder to which the present invention relates is the type which determines the angle of arrival of the phase front of a signal transmitted by, or reflected from, an object to be located in angle.
A system of the particular type to which the present invention applies is described in U.S. Pat. No. 3,924,236. That prior art, sometimes referred to as a synthetic aperture system, requires a delay line constructed to exacting requirements and, therefore, relatively expensive.
The manner in which the present invention improves upon the prior art, in view of the aforementioned prior art disadvantage, and also in other ways will be evident as this description proceeds.